1. Field of the Invention
The invention relates generally to a table and particularly to a modular wire frame table used in environments having stringent particle generation requirements such as a fabrication clean room.
2. Related Art
Fabrication clean rooms, for example fabrication rooms for manufacturing submicron wafers for computer microchips, have stringent requirements for particulate generation. Contamination of the manufacturing process from particulates has become a serious concern.
One of the ways to combat particulates in fabrication clean rooms is to use a wire frame table. The wire frame table has a surface made of wires to allow recirculated air to flow through the table surface. The wire surface suppresses turbulence which would otherwise be created as a result of air flow impinging on solid table tops. To further combat particulate generation, the wire frame table is constructed of stainless steel and is electro-polished or electro-plated to withstand corrosion from acid spills or fumes from acids.
In the wire frame tables currently used in fabrication clean room environments, the wires are welded onto the table frame. A problem with this construction is that solutions used during electro-polishing or electro-plating become entrapped in the spot-welding grooves and cause corrosion in the grooves afterwards. Consequently, dirt accumulates in the corroded grooves and eventually propagates into the surrounding environment. The table legs cause similar problems, because they too are welded onto the frame.
Still another problem with welding of the wires to the table frame is warpage during welding. With warpage, the wire frame table top is no longer even, especially because the amount of warpage varies from wire to wire. In order to provide a flat or an even work surface, the welding process must be scrutinized carefully for each weld and as a result, the process becomes prohibitively expensive.